The purpose of this project is to study the structures of new compounds of natural origin which may have physiological properties. Plant constituents of Acacia vilos, Diospyros virginiana, Krameria ixica, Sassafras albidum, melochia tomentosa (potential carcinogens) and Schinus terebinthifolius (respiratory and allergic reactions) were determined. The pheromones of various species of ants and termites were studied.